Outer Limits 4x4 Board

Pulled my uhf out of my hilux and put it into the vitara all works great until i start the engine and then i get a buzzing sound that increases with revs. I put a sound filter on which made no difference and i can even run the power off a car parked next to me and it will still do the same thing if the vitaras engine is running which makes me think its not alternator noise if i am running power off a seperate vehicle. I am thinking electrical interference but have no idea how to check for that. Can anyone help???

I'm thinking too much AC in the system. Perhaps a regulator problem.

Try attaching the UHF power wires directly to the battery terminals, as the battery will smooth-out the AC for you.

Also, if you can get a second good regulator, swap it and see if that helps.

Yeah the first place i connected it to was the battery and then the stereo and then the cigarette lighter and then the fuse box and then a second car all just as bad as the next. Will try regulator cheers any other ideas?.

It could be RF noise generated by the brushes in your alternator, but I'm not sure what the options are for suppressing it. I guess I'd start by checking all the earth connections you can find in your engine bay - make sure they're clean and tight, and see if that makes a difference.

Hi guys i have some new info.I decided to take the aerial of the front bumper to check to see if the interference is aerial related. Well if i hold the aerial and walk to the back of the vehicle while transmitting or receiving the interference stops. As soon as the aerial gets near the front of the vehicle if i recieve or transmit the buzzing noise comes back. This is only with the engine running. Any ideas on what could cause buzzing sounds when receiving or transmitting that is aerial related to the front of the vehicle. At least i now know that it is not comming through the power source or the units earth.

????

you have a noisy electrical system. I imagine you most likely have a petrol.

make sure your antenna's earth connection is good.

Check your coax termination on each end (particularly the shield) and make sure it's a good clean solid connection.

see if you can borrow someone elses radio (pref different brand/model) and plug it in to your antenna, just to rule out poor filtering on your particular radio.

Use a better quality Co-Ax.

There may be inline filters available for UHF (i know there was for 27 Mhz) Speak to a specialist radio store for one of these.

Replace your spark plug leads (if applicable) with higher quality leads.
replace suppressor on the dizzy.

look in to the regulator of the alternator to see if it may need replacing.

Follow the things in this order listed, as they go from cheapest to most expensive

Or you could just mount your antenna on the back/roof. The fact that it still happened whilst running of a seperate unconnected battery means it is coming in via rf and not ignition.